1. Field of the Invention
This invention relates generally to photosensor control units, and more particularly to a photosensor control unit adapted to be used with an outdoor lighting system wherein a light sensor is positioned within the lighting system adjacent a plurality of LEDs or the like of the lighting system.
2. Description of Related Art
Outdoor lighting systems are commonly used to illuminate selected areas at night. Light sources of outdoor lighting systems are typically turned on in response to low ambient light conditions (e.g., after sunset) and turned off during high ambient light conditions (e.g., during daylight hours). Many outdoor lighting systems with automatic on-off control systems responsive to ambient light conditions include photoconductive cells (i.e., photocells).
Known outdoor lighting fixtures with automatic on-off control include photocells sensitive to visible light. Such photocells cannot distinguish between ambient light and light produced by the lighting fixtures. In order to prevent the photocells from being influenced (e.g., triggered) by the light produced by the lighting fixtures, the photocells must be oriented (i.e., aimed) away from the light exiting the lighting fixtures. As a result, the photocells are often positioned in locations where they are subject to harmful conditions.
For example, known street lighting fixtures have photo-controls positioned on upper surfaces of housings. The photo-controls are subjected to direct sunlight all day long. Sunlight includes destructive ultraviolet radiation, and solar heating causes the components of the photo-controls to be heated to temperatures in excess of 85 degrees Celsius. In addition, the upper surface mounting of the photo-controls also subjects the photo-controls to harsh weather, debris from trees, and bird droppings. The debris from trees and bird droppings can obscure plastic windows through which light passes, shading internal photocells from the ambient light and causing the street lighting fixtures to operate for longer hours. These and other exposure conditions often eventually lead to failure or unpredictable performance of the photo-controls and/or the street lighting fixtures. Furthermore, top side socket mounted photo control units frequently leak water into the fixture, which can cause internal failures.
It would be advantageous to have a lighting assembly with automatic on-off control that does not include a photo-control positioned on an upper surface of the lighting assembly.